An organic thin-film photovoltaic cell is a solar cell utilizing an organic thin-film semiconductor based on a combination of a conductive polymer, fullerene, etc. The organic thin-film photovoltaic cell is advantageous in that as compared with a solar cell based on an inorganic material, it can be manufactured through an easy process, thereby realizing low cost. However, the organic thin-film photovoltaic cell has a drawback that a photoelectric conversion efficiency and lifetime of the organic thin-film photovoltaic cell are inferior to those of conventional inorganic photovoltaic cells. A cause of the drawback is that there are a multiplicity of parameters whose control is difficult, such as semiconductor material purity, molecular weight distribution and orientation, with respect to the organic semiconductor for use in the organic photovoltaic cell.
Various elaborations for enhancing the photoelectric conversion efficiency of the organic photovoltaic cell have been made.